In GB-A-2146588 there is described an ink cartridge with an internal valve assembly including a valve seat, and a valve member urged against the seat by a coil spring, the valve member being axially inwardly displaceable to open the valve to allow ink to flow out of the cartridge. Described in WO 01/64452 is an ink cartridge including an internal valve assembly including a valve seat and a resilient diaphragm separating a chamber, which is in communication with ambient atmosphere via an air port, and ink transfer chamber so that the diaphragm is deformed to open the ink path from the main ink chamber when there is a reduced pressure in the ink transfer chamber.